1. Field of the Invention
The present invention relates to locking mechanisms for doors, and more particularly, to those that include multiple bolt latches.
2. Description of the Related Art
It is well known in the art that the latching bolts of locking mechanisms should protrude outwardly a sufficient distance to effectively engage in with the cooperating latch opening that will receive the latching bolts. It is commonly believed that one inch is the minimum distance that will effectively lock a door or other opening using a locking mechanism.
A very popular model for such locking mechanisms for doors is marketed under the trademark Mul-T-Lock, by Mul-T-Lock, Ltd., Industrial Zone, Yavne 70653, Israel, as shown in the attached sales literature. The design for this locking mechanism is shown in FIGS. 1 through 4. The distance that latching bolts (not shown) travel is transmitted by rods R and R' in response to the pivotal movement of linkage members L and L'. These linkage members have adopted, so far in the designs available in the market, the shapes shown in FIGS. 1 through 4. Linkage mechanisms L and/or L', in turn, respond to the rotational movement of partially teethed disk D and/or D' which in turn is caused by the rotation of key cylinder C and its associated gear in meshed engagement with the teethed portion of disk D or D'. Then, it is apparent that the distance traveled by rods R or R', and consequently, by the latching bolts on their ends, is the difference between the separations indicated as O-B and O-A in FIGS. 1 and 2 for one of the designs. The other design, the one shown in FIGS. 3 and 4, improves somewhat the problem of fabricating a simpler linkage member. However, the distance traveled by latching the latching bolts is the same and it is similarly determined by the difference between points O'-B' and O'-A'.